豆瓣绿营养器官解剖结构
时间:2018-07-31 21:44 来源:毕业论文 作者:毕业论文 点击:次
| 摘要：采用石蜡切片技术，在光学显微镜下观察豆瓣绿(Peperomia tetraphylla)根、茎、叶以及叶柄的解剖结构。结果表明：豆瓣绿根由表皮、皮层和文管柱组成，木质部脊数为4，皮层较厚且有较多晶体；茎由表皮、基本组织和文管束组成，表皮外侧有单细胞毛，基本组织中具散生文管束并存在油细胞类异细胞；叶片由表皮、叶肉和叶脉构成，具有角质层和蜡质层，仅下表皮分布不等型气孔器，叶肉分为贮水组织和同化组织，界线分明；叶柄由表皮、基本组织和文管束组成，文管束呈弧形排列。豆瓣绿的营养器官根中有晶体；茎结构更趋向于单子叶植物，表皮外侧有单细胞毛，基本组织中存在油细胞类异细胞；叶肉由贮水组织和同化组织组成，这些特征比较特殊。根存在周皮、晶体，茎具单细胞毛和大量薄壁细胞，叶具蜡质层、角质层和贮水组织等特征与其抗旱性有关。26535 毕业论文关键词：豆瓣绿；营养器官；解剖结构；抗旱性 Study on Anatomical Structures of Vegetative Organs Of Peperomia tetraphylla Abstract：This paper deals with the anatomical structures of vegetative organs, which includes roots and stems and leaves of Peperomia tetraphylla, with the light microscope by using paraffin method. The results are as follows. The roots of Peperomia tetraphylla consisted of epidermis, cortex and vascular cylinder with four xylem ridges. The cortex was thicker with single crystal scattered. Stems consisted of epidermis, basic tissue and vascular bundle. There were unicellular hairs on epidermis. Oil cells belonging to idioblasts existed in basic organization with vascular bundles scattered. Blade consisted of epidermis, mesophyll and veins with cuticle and waxy layer. There were anisocytic type stomatal apparatus only in the lower epidermis.Mesophyll was pided into the water storage tissue and assimilation tissue. Petioles consisted of epidermis, basic tissue and vascular bundle which were arranged in the form of the arc.The special features were as follows: Peperomia tetraphylla had single crystal in the vegetative organs of roots; the structure of the stems were more similar to that of monocotyledon, there were unicellular hairs besides epidermis and oil cells belonging to idioblasts existed in basic organization; mesophyll were pided into the water storage tissue and assimilation tissue and so on. There were periderm and single crystal in roots, a large number of parenchyma cells, unicellular hairs in stems, and cuticle,waxy layer and water storage tissue in leaves.Those characters were associated with drought resistance. Key words：Peperomia tetraphylla;Vegetative organs; Anatomical structures; Drought resistance 目 录 引言 1 1材料与方法 2 1.1供试材料 2 1.2实验方法 2 2结果与分析 3 2.1根 3 2.2茎 3 2.3叶 3 3讨论 7 3.1豆瓣绿营养器官的特殊结构 7 3.2豆瓣绿营养器官的结构与抗旱性的关系 7 致谢 8 参考文献 8 引言 豆瓣绿(Peperomia tetraphylla)属于胡椒科(Piperaceae)草胡椒属，多为小型一年生或多年生常绿肉质草本，属观叶植物，原产于西印度群岛、巴拿马、南美洲北部。园林中经常应用的为多年生常绿肉质草本，株高20～30厘米，枝叶多汁，四叶轮生或单叶对生；叶片肥厚且有鲜艳的色彩或斑纹；多为夏秋季开绿白色两性花，穗状花序顶生；果实极小，长圆形浆果，顶端有嘴，不开裂。豆瓣绿整体极具观赏价值[1-4]。豆瓣绿喜阴湿和半阴湿的环境，宜在间接光线下生长，即能在室内干燥的条件下长期观赏，因而适于室内观赏[5]。 (责任编辑：qin) |